This invention relates to a water production system for making potable water in an environment of humid tropical air and a cooling fluid, preferably cold deep ocean water. The water production system comprises a heat exchanger, means for controlling the volume of the cooling fluid passing through the heat exchanger, and means for enhancing the rate of at which water vapor is condensed including selectively a positive air pressure dome system for enhancing the humidity, condensation rate, and water quality, and a continuous coil disposed in the flow of humid air to condense additional potable water, and means for vibrating elements of the system to increase condensation.
The improvements of this important invention comprise enhancing the humidity of the humid air, condensation rate, and water quality of the condensation system, which may include a positive air pressure dome system having a sheeting cover supported by the positive air pressure. The positive air pressure can be supplied by at least one air fan. The sheeting cover is preferably free of contact with the heat exchanger contained therein, and the sheeting cover may be secured to the ground at its peripheral edge. The positive pressure within the dome system can enhance the condensation rate and air borne water contaminants can be reduced. Utilizing the sheeting system allows flexibility for expansion of and the ability to cover a number of additional heat exchangers which can be disposed laterally at the same elevation and still be kept under an extended dome system.
Preferably, the at least one air fan includes a ducted air fan humidifier, in which the humidity levels within the dome system can be further enhanced to increase the condensation rate. The means for governing may further comprise at least one continuous coil looped over a coil support structure that is disposed in the flow of humid air to condense additional potable water from the humid air. The at least one continuous coil is supplied with cooling fluid entering or discharging from the heat exchanger. The at least one continuous coil may be loosely looped over a coil support structure. Additionally, the means for governing may comprise means for vibrating the at least one continuous coil and more generally means for vibrating the tubes of the heat exchanger.
This improved condensation system may further comprise means for controlling the cold water transported through the heat exchanger based on at least one of the temperature of the cooling water discharging from the heat exchanger, the temperature of the water in or discharging from a reservoir that collects the water discharging from the heat exchanger, and the differential between the temperature of the water entering the heat exchanger and the temperature of the water leaving the heat exchanger. Specifically, the means for controlling the cold water transported through the heat exchanger may comprise an inlet reservoir for receiving cold water, an outlet reservoir for receiving the cold water discharged from the heat exchanger, and each of the inlet reservoir and the outlet reservoir containing a volume of cooling water having an inlet upper level and an outlet upper level, respectively.
The inlet upper level may be maintained by at least one float valve which controls the volume of cold water entering the inlet reservoir; the outlet upper level is controlled by at least one moveable weir, and a cold water circuit may extends from the inlet reservoir through the heat exchanger to the outlet reservoir. Preferably, each of the inlet reservoir and the outlet reservoir is un-pressurized. The inlet end of the cold water circuit is disposed below the inlet upper level, and the outlet end of the cold water circuit is disposed below the outlet upper level. Means for measuring the temperature of the cooling water near the outlet end of the water circuit and producing a signal to control movement of the at least one moveable weir in response to the temperature is required. Additionally, the means for measuring may include measuring the temperature of the cooling water near the inlet end of the water circuit for determining the differential temperature. It is preferred that the controlled flow of cold water be siphoned through the water circuit by a vacuum created when the at least one moveable weir is lowered bringing down the outlet upper level in the outlet reservoir in response to the temperature measurement.
Unlike the present invention, U.S. Pat. No. 5,675,938 issued in 1997 to McLorg for a desert envitalization system with variable volume pneumatic polydome enclosure discloses an inflatable enclosure for condensing and collecting water vapor from solar heated seawater. The pneumatic enclosure is maintained at a positive pressure by an inflation fan. The '938 patent collects condensate that is plumbed to a ballast system which helps hold up the dome during the nighttime; it does not produce condensate for drinking water, nor does it protect a fluid heat exchanger. It is a closed hydrological system whereas the instant invention is open but internally pressurized.
Moreover, U.S. Pat. No. 6,440,275 issued in 2002 to Domen for solar stills for producing fresh water uses an inflatable bladder system. Domen's solar still does not use a heat exchanger employing cold water and has a closed environment whereas the instant invention is a positive pressure but open environment system.
Furthermore, U.S. Pat. No. 4,956,936 issued to Sprung in 1990 for a method and system for purification of water for greenhouse structures teaches a device and method for the generation and subsequent condensation and collection of water vapor within the volume of a greenhouse. The '936 patent teaches only water production for irrigation to plants in a closed environment system and the water produced is not collected from an internal heat exchanger. Also see U.S. Pat. No. 4,741,123 issued to Gauthier in 1988 for a greenhouse equipped with a watering system which captures and distributes condensate water from the morning and evening dews. The '123 patent is used for watering plants only and not for potable, commercial, or industrial water production. Additionally, it is not related to the use of a heat exchanger system.
U.S. Pat. No. 3,498,077 issued in 1970 to Gerard et al. for an atmospheric water recovery method and means for obtaining potable water from atmospheric air, in which cold deep seawater is pumped through a heat exchanger that reacts with humid air to produce condensate potable water that is collected in a tank. The '077 patent does not use a moderated environment to condense water vapor and it does not teach the use of a dome system to control aerial contamination of the freshwater produced, nor does it control the flow of deep sea water based on temperature.
Design Patent D363,993 issued in 1995 to Johnson et al. for an inflatable shelter does not teach a dome system used for the production of freshwater nor does it indicate a pressurized air-flow system for inflation. Other background patents have been included in the provisional application referenced above.
The citation of the foregoing publications is not an admission that any particular publication constitutes prior art, or that any publication alone or in conjunction with others, renders unpatentable any pending claim of the present application. None of the cited publications is believed to detract from the patentability of the claimed invention.